The existing ground detection system and wall surface detection system of a mobile robot each comprises at least one set of an infrared emission tube and an infrared receiving tube, the infrared emission tube is used for emitting infrared light, and the infrared receiving tube is used for receiving infrared light. The infrared light emitted by the infrared emission tube is reflected by the ground or a wall surface, and then is partially received by the infrared receiving tube. Different intensities of the infrared light received by the infrared receiving tube exhibit signals of different magnitudes. In the prior art, a signal of the infrared receiving tube (denoted as X1) is captured by turning on the infrared emission tube for a period of time, and then the infrared emission tube is closed for a period of time to capture the signal of the infrared receiving tube (denoted as X2), a difference (denoted as X3) is calculated between X1 and X2, and it is judged (determined) whether X3 stays within a preset threshold range so as to judge in which environment the mobile robot is placed.
However, once the design of the mobile robot is finalized, the sensitivity of the infrared receiving tube is fixed, and it is difficult to ensure that the ground detection system and the wall surface detection system can operate normally in three special environments, for example, on a ground or wall surface irradiated by (exposed to) strong light, a ground or wall surface with normal brightness, and a ground on which a black carpet is laid or a wall surface covered by a black light-absorbing material. In the environment of the ground or wall surface irradiated by strong light, no matter whether the infrared emission tube is turned on or turned off, since ambient light contains infrared light components, the infrared light with higher intensity is received by the infrared receiving tube, so that the infrared receiving tube is always in a saturated state, there is almost no difference between X1 and X2, and then the mobile robot misjudges that the ground is in a cliff state, and thereby takes an action to avoid danger; or moves away from the wall surface and cannot get close to the wall edge to perform actions such as sweeping, mopping, and the like. In the environment of the ground on which a black carpet is laid or the wall surface covered by a black light-absorbing material, no matter whether the infrared emission tube is turned on or turned off, the infrared light emitted by the infrared emission tube is mostly absorbed by the black carpet or the black material, and the small part of the infrared light is not enough to exhibit a significant change in magnitude of the signal of the infrared receiving tube, thus it is also misjudged that it is in a cliff state or cannot get close to the wall edge.